Sometime in 2062, Deryl Dedmon will finish serving his prison sentence. Actually, it will be only the first part of his sentence — the 50-year lockdown he earned himself when he pleaded guilty to a hate crime. He’ll then be transferred to a Mississippi state prison, where he’ll begin serving two concurrent life sentences. Dedmon is only 19 years old, so he could easily make it through the federal stretch and serve a decade or more the state term. Either way, with no possibility of parole, he will die in prison.

You may already know about Dedmon’s sentence. It was Dedmon who was behind the wheel of an F-250 pickup truck in 2011 when he and some friends went looking for African Americans to assault or, as they put it according to later statements, to go “f— with some n——.” They found 49-year-old James Anderson in a parking lot, beat him and shouted racial epithets at him — and then Dedmon drove his car over him. Every unwatchably awful moment of that murder was caught on surveillance video. So you might have already said, “It serves him right.”

And yet there’s the matter of Dedmon’s age. The Supreme Court has been wrestling of late with trying to determine just how old someone has to be for courts to impose just what kinds of sentences — and still remain within the bounds of the Eighth Amendment’s prohibition against cruel and unusual punishment. It’s a conversation that badly needs having. More than 2,500 people are serving life sentences nationwide for crimes they committed when they were juveniles; 71 of those lifers were 14 or younger when they went afoul of the law.

In 2005, the court ruled out the death penalty for defendants who commit their crimes when they are below 18 years old. In 2010, the justices decided similarly concerning sentences of life without parole for minors whose crimes do not involve a death. The day before the Dedmon sentencing, the court heard arguments in yet another such case, this time asking whether it is ever appropriate for a minor to be locked up for life. The appellants in that case are two boys who committed their crimes when they were 14.

Though six other young males were involved with Dedmon in killing Anderson, the only three charged with a federal hate crime were 18 or older at the time of the killing. But Mississippi law is a lot less concerned with drawing a line between juveniles and adults. At the judge’s discretion, a sentence of life without possibility of parole can be imposed on defendants as young as 13 for certain crimes. And any defendant 13 or older must be tried as an adult for any crime for which the death penalty or life without parole is a possible sentence.

But even if courts universally accept 18 as the minimum age at which any defendant can be tried and sentenced as an adult, there are still problems with such a standard, not the least being that the defendants’ brains just don’t work right — if by “right” we mean rationally, coherently and with a reasonable sense of consequences. The central inquiry ought to be, Do they understand the full meaning and the likely outcome of their acts, and do they have the power to prevent themselves from committing them? Neuroscientist Dr. Jay Giedd of the National Institute of Mental Health has made a career out of studying the free-fire zone that is the teen brain and, along with other investigators, has come up with some insights into just how long it takes the full suite of cognitive software to come online.

The prefrontal cortex is the CEO of the brain, the place reflection, impulse control, foresight, perspective, reasoning and all of the other things we associate with adult behavior live. The prefrontal is also known as the seat of sober second thought. But it’s not until we’re in our mid- to late 20s that that region’s neural wiring is fully laid out and engaged. Until then, we rely more heavily on the amygdala, which resides — appropriately — in the basement of the brain and is home to rage, fear, bravado, xenophobia and all of the other human impulses that still have a bit of adaptive value but need to be kept on a very, very short leash.

The surging hormones of adolescence similarly act as an accelerant for the wildfires that can break out in the brain’s limbic system — another seat of emotion. After the hormones have subsided — typically but not always in the late teens — the limbic settles down some, even if the amygdala does not. So while it’s hard to argue that a mob hit man or a contract killer or even an adult thug who robs a liquor store and shoots the clerk did not have the advantage of a fully functioning brain with which to make clearly conscious choices, that’s a tougher call to make when it comes to a kid — just as it is when it comes to the mentally retarded or the brain damaged or the schizophrenic.

The problem, of course, is where to set a cutoff point. Should a boy who commits a murder one day before his 18th birthday have it easier than a boy who commits the same crime one day after his? Suppose your exact hour of birth was 5 p.m. and you commit your crime at 4 p.m.? During the most recent Supreme Court arguments, Justice Samuel Alito posed the birthday question, asking why in the world you’d spare a perp who’s one day shy of 18 a life sentence for the “worst possible string of offenses.” Justice Steven Breyer then — predictably — yielded to the law-school temptation to turn the question on its head. “What’s the minimum age,” he asked the counsel arguing in favor of life terms for minors, “or is there any constitutional minimum at all, [for giving] a child life without parole?” In other words, would you lock up an 8-year-old forever?

The clear and certain answer to the cutoff question is that there is no clear and certain answer. In the case of criminal sentencing, then, it might be wise to take not just the date of birth into consideration but development level too, with character testimony and psychological screening helping to determine just how cool and deliberate a young person’s state of mind was when the crime was committed.

There are some crimes that will always leave us feeling nothing but despair — for the victims, for the human race and its capacity for doing the unspeakable. Deryl Dedmon’s is one such crime. But we are also a species that values — or professes to value — redemption. The same softness in the clay of Dedmon’s brain that made it easier for him to act without humanity makes it at least possible that he could one day turn into something better than he is. Children must often serve time — even a great, great deal of time — but wisdom must prevail in determining how much.